Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020440 (hypercapnia)
 7,939 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Auditory, visual and somatosensory evoked potentials (EPs), recorded epidurally from 31 chronically implanted male Long-Evans rats, were studied to examine the pattern of sensory effects caused by hypercapnia. Recordings were obtained before exposures, 10-20 min after the beginning of exposure to CO2 in synthetic air, and 30 min after the end of exposure. Previous recordings revealed no substantial effects of the extended recording period itself. Blood pH during an average exposure of 18.8% CO2 was about 7.1. During this level of CO2 exposure the somatosensory response was almost completely abolished, but the latencies of early detectable components were not affected. In contrast, the latencies of all brainstem auditory evoked response components and the 1-5 interwave time increased, whereas amplitudes were only slightly affected. Amplitudes and latencies of early and late components of the flash EP were decreased and lengthened, but the after-discharge components appeared to be most sensitive to CO2. Concentration-response relationships were examined by exposure of rats to 8 and 16% CO2. The most sensitive EP parameter was average amplitude of the late somatosensory EP components. These results suggest that EPs might be useful for assessing acute metabolic disturbances as well as more commonly assessed neurologic disorders.
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PMID:Effect of acute respiratory acidosis on multimodality sensory evoked potentials of Long-Evans rats. 258 91

From this and the previous article, the following points may be offered in summary: When comparing the elderly age group with the general population, the incidence of migraine headaches decreases with age, whereas other etiologies such as glaucoma, temporal arteritis, and cerebrovascular disease may assume a more prominent role in the differential diagnosis. Patients in the geriatric population are frequently taking a multitude of medications, and it is extremely important to carefully evaluate these for possible precipitants of headache. Furthermore, in elderly patients with other potential medical problems, particular attention should be paid to the possibility of various systemic causes of headache. Therapy for specific headache disorders should be tailored to the individual patient. Consider the patient's overall general, psychological, medical, and neurologic background. The physician must be aware of possible interactions of medications with the therapeutic intervention, as well as possible poor tolerance to specific medications due to preexisting medical or neurologic disorders. A complete history, obtaining information on the temporal pattern of headache, the distribution of pain, and precipitating and alleviating factors, is extremely important in evaluating the elderly patient. A careful physical examination, paying particular attention to possible disorders of extracranial structures, is indicated. A neurologic exam, including basic tests of higher cortical function, should be obtained. Important additional laboratory investigations include a complete blood count, erythrocyte sedimentation rate, and basic blood chemistries. Arterial blood gases should be obtained in patients who have pulmonary disease, a history suggestive of sleep apnea, or other disorders that may produce hypoxia and hypercarbia, resulting in vascular headache.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Headaches in older patients: Ddx and Tx of common nonvascular causes. 405 33

Albumin concentration in cerebrospinal fluid (CSF) and plasma was determined in 44 cadavers divided into three groups on the basis of death agony duration. The same was determined in a control group of 42 patients with no demonstrable neurological disease. Following Schuller's method, the evaluation of the blood CSF barrier permeability was based upon the rate of albumin transfer from plasma to CSF. An average increase of 9% in blood CSF barrier permeability was found in cases of a long-duration death agony but not in cases of short-duration death agony (sudden deaths) or in the control group. We consider these results to be related to the hypoxia and hypercapnia which characterize the agonic suffering period. Therefore, we conclude that the postmortem determination of the rate of albumin transfer from plasma to CSF could be a reliable indicator of the duration of the agonic process.
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PMID:Forensic significance of postmortem estimation of the blood cerebrospinal fluid barrier permeability. 664 40

A report is given on a 66 years old patient with severe idiopathic hypoventilation. Two years ago the disease had developed rather suddenly with severe hypoventilation during sleep, accompanied by marked hypoxemia and hypercapnia with pCO2-values above 100mm Hg and respiratory acidosis. No pulmonary, cardiac or neurological disease was found. After failure of two attempts of stimulation of the phrenic nerve the patient was admitted to a respiratory intensive care unit and ventilated by a respirator during sleep. After improvement of this general condition he was discharged at first only in the daytime, later he could be discharged fully from the unit, after a respirator had been installed in his home. Now the patient is connecting himself to the respirator during sleep and since 20 months is so in a tolerable condition. The indications for home-respirator treatment are discussed.
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PMID:[Home-respirator treatment in idiopathic hypoventilation (author's transl)]. 678 59

A central apnea is a disorder characterized by apneic events during sleep with no associated ventilatory effort. Central sleep apnea syndrome is characterized by repeated apneas during sleep resulting from loss of respiratory effort. Although the etiology of central apnea remains obscure in most cases, current investigations into breathing control system during sleep and association with certain diseases have pointed out possible mechanisms. Ventilation during sleep is highly dependent on the nonbehavioral control system. As a result, any diseases affecting this control system could influence the breathing patterns while the patient is asleep. As our results show, most patients with central sleep apnea and without congestive heart failure had quantifiable abnormalities like diminished carbon dioxide response curves. Neurological diseases affecting the brainstem are able to produce breathing pattern disorders in sleep. Well-known neurological diseases such as arteriosclerosis in the elderly, infarctions, tumors, hemorrhage, accidents with damage of this region, encephalitis, poliomyelitis or other infectious diseases may cause central apnea during sleep, even if in wakefulness no abnormalities of breathing patterns are present. Apneas cause hypoxemia, hypercapnia and increased sympathicotonia. This may result in development of pulmonary artery hypertension or systemic hypertension. Published results demonstrate that medical treatment is ineffective in these patients. Implantation of a diaphragm pacing device is an invasive measure, the efficacy of the diaphragm pacing has not been proven by long-term trials, however. Mechanical ventilation was shown to be the most efficient treatment. A therapeutic procedure using a timed n-BiPAP device is able to normalize blood gases during sleep. The n-BiPAP prevented the development of severe pulmonary artery hypertension during sleep.
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PMID:Central sleep apnea. 904 68

Respiratory handicap due to neurological diseases is often underestimated. Given clinical signs are either mild or absent, systematic measurement of the vital capacity is the best mean to detect in practice the restrictive syndrome. The onset of home mechanical ventilatory support should be decided at steady state, apart from episodes of acute respiratory failure. Two types of indications should be distinguished. Necessary ventilation aims at supplying over day and night the respiratory insufficiency incurred by the paralysis of respiratory muscles. Although the criteria for the use of such a supply differ according to the neurological disease, a daytime hypercapnia above 45 mmHg is widely accepted in the literature. It is otherwise established to use first a non invasive technique, while tracheostomy is secondarily proposed in case of failure of these techniques. The application of this therapeutic strategy in Duchenne de Boulogne muscular dystrophy showed that, given that tracheostomy will become necessary in this evolutive disease, proposal of an early tracheostomy is not nonsensical. By contrast, preventive ventilation aims at preventing from the aggravation of the restrictive syndrome in those patients with no criterion for necessary ventilation. It has been proved ineffective in Duchenne muscular dystrophy through a controlled clinical trial.
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PMID:[Long-term ventilation at home in adults with neurological diseases]. 980 60

Acute confusional syndrome, or delirium, is a transitory mental state characterized by the fluctuating alteration of awareness and attention levels. We present the case of a patient with acute confusional syndrome associated with obstructive sleep apnea syndrome (OSAS) aggravated by metabolic acidosis induced by oral acetazolamide treatment.A 70-year-old man with no history of neurological disease was referred with a clinical picture consistent with acute confusional syndrome presenting between midnight and dawn. During the admission examination infectious, toxic, and neurologic causes, or those related to metabolic or heart disease were ruled out. Arterial blood gases measured during one of the nighttime episodes of acute confusional syndrome showed mild hypoxia and hypercapnia with mixed acidosis. Signs and symptoms suggestive of OSAS had been developing over the months prior to admission, with snoring, sleep apnea, and moderate daytime drowsiness. Polysomnography demonstrated severe OSAS with an apnea-hypopnea index of 38. Mean arterial oxygen saturation was 83%; time oxygen saturation remained below 90% was 44%. The attending physician ordered the withdrawal of oral acetazolamide, which was considered the cause of the metabolic component of acidosis. Treatment with continuous positive airway pressure was initiated at 9 cm H2O, after a titration polysomnographic study. The patient continued to improve.OSAS, for which very effective treatment is available, should be included among diseases that may trigger acute confusional syndrome.
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PMID:[Acute confusional syndrome associated with obstructive sleep apnea aggravated by acidosis secondary to oral acetazolamide treatment]. 1516 96

Brown-Vialetto-Van Laere syndrome (BVVLS) is a rare neurological disease characterized by sensorineural hearing loss and multiple cranial nerve palsies, usually involving the VIIth and IXth to XIIth cranial nerves. We describe the clinical and pathological features of a 33-year-old woman with BVVLS. The patient developed progressive exertional dyspnea, with clinical and laboratory findings of right-sided heart failure and pulmonary hypertension. She developed status epilepticus in the setting of cardiac deterioration and respiratory infection, and died of cardiogenic and septic shock. Autopsy disclosed bilateral neuronal loss and gliosis in the inferior colliculi, locus coeruleus and facial and vestibular nuclei. Cor pulmonale is a complication of hypoventilation-induced hypoxia and hypercapnia and had not yet been reported in BVVLS.
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PMID:Cor pulmonale in a patient with Brown-Vialetto-Van Laere syndrome: a case report. 2105 69